Apache Cassandra is a NoSQL database intended for storing large amounts of data in a decentralized, highly available cluster.
\nCassandra or Apache Cassandra is a distributed database system which manages large amounts of structured data across different commodity servers by providing highly available service with no point of failure.
\nNoSQL refers to a database with a data model other than the tabular relations used in relational databases such as MySQL, PostgreSQL, and Microsoft SQL.
\nThe Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance.<\/p>\n
Cassandra is one the popular and robust distributed database management system. It is known for providing high availability with no single point of failure.
\nIt has one of the awesome feature that is asynchronous replication between multiple nodes without requiring master nodes.
\nCassandra is a reliable, clusterable, highly-scalable database capable of handling large quantities of data on commodity hardware.
\nIf you have big data needs, and are looking for a proven open source solution that has received battle testing from many large companies, then Cassandra may be exactly what you\u2019re looking for.<\/p>\n
If you have a CentOS 7 server, this guide will get you up and running with a single Cassandra node.
\nIt will use pre-packaged Cassandra distributions built for CentOS, making installation and upgrades a snap.
\nYou can then build it out by performing additional installations on other servers, then clustering the resulting instances for higher scalability and reliability.<\/p>\n
This article will guide you on how to install Apache Cassandra on CentOS 7 Server.<\/p>\n
CentOS 7 Cassandra systemd service file<\/p>\n
# \/usr\/lib\/systemd\/system\/cassandra.service<\/p>\n
[Unit]
\nDescription=Cassandra
\nAfter=network.target<\/p>\n
[Service]
\nPIDFile=\/var\/run\/cassandra\/cassandra.pid
\nUser=cassandra
\nGroup=cassandra
\nExecStart=\/usr\/sbin\/cassandra -f -p \/var\/run\/cassandra\/cassandra.pid
\nStandardOutput=journal
\nStandardError=journal
\nLimitNOFILE=100000
\nLimitMEMLOCK=infinity
\nLimitNPROC=32768
\nLimitAS=infinity
\nRestart=always<\/p>\n
[Install]
\nWantedBy=multi-user.target<\/p>\n
How To Install Cassandra on CentOS 7<\/p>\n
Step 1: Install Java<\/p>\n
First, you\u2019ll follow a simple best practice: ensuring the list of available packages is up to date before installing anything new.<\/p>\n
yum -y update<\/p>\n
At this point, installing lsyncd is as simple as running just one command:<\/p>\n
yum -y install java<\/p>\n
tar -zxvf jdk-8u121-linux-x64.tar.gz<\/p>\n
mv jdk-8u121-linux-x64.tar.gz \/root\/software\/<\/p>\n
vi \/etc\/profile.d\/java.sh
\n# Uncomment the following line to set the JAVA_HOME variable a
\n#JAVA_HOME=\/usr\/lib\/jvm\/jre
\nexport JAVA_HOME=\/usr\/java\/jdk1.8.0_121
\nexport JRE_HOME=\/usr\/java\/jdk1.8.0_121\/jre
\nexport PATH=$PATH:\/usr\/java\/jdk1.8.0_121\/bin
\nexport CLASSPATH=.\/:\/usr\/java\/jdk1.8.0_121\/lib:\/usr\/java\/jdk1.8.0_121\/jre\/lib<\/p>\n
source \/etc\/profile.d\/java.sh
\nexport
\nalternatives –config java
\nalternatives –install \/usr\/bin\/java java \/usr\/java\/jdk1.8.0_121\/bin\/java 5
\nalternatives –config java<\/p>\n
Step #2: Add the DataStax Community Repository<\/p>\n
vim \/etc\/yum.repos.d\/datastax.repo<\/p>\n
Add the following information to the file you\u2019ve created, using i to insert:<\/p>\n
[datastax]
\nname = DataStax Repo for Apache Cassandra
\nbaseurl = http:\/\/rpm.datastax.com\/community
\nenabled = 1
\ngpgcheck = 0<\/p>\n
Step #3: Install Apache Cassandra 2<\/p>\n
At this point, installing Cassandra is as simple as running just one command:<\/p>\n
yum -y install dsc20<\/p>\n
Step #4: Get Cassandra Running<\/p>\n
Start-Up Cassandra<\/p>\n
systemctl start cassandra<\/p>\n
Check Cassandra Service Status<\/p>\n
systemctl status cassandra<\/p>\n
Enable Cassandra to Start at Boot<\/p>\n
systemctl enable cassandra<\/p>\n
Enter the Cassandra Command Line<\/p>\n
cqlsh<\/p>\n
With Cassandra installed, we must now start the daemon via systemd.
\n\/etc\/init.d\/cassandra start<\/p>\n
The systemd unit is now created. Use \u201csystemctl start cassandra\u201d to launch the new unit.<\/p>\n
systemctl enable cassandra.service<\/p>\n
While the database should be running, it is not yet configured to launch on boot. Let\u2019s tell systemd that Cassandra should automatically launch whenever your system boots.<\/p>\n
[root@cassandra ~] systemctl status cassandra<\/p>\n
cassandra.service – SYSV: Starts and stops Cassandra
\nLoaded: loaded (\/etc\/rc.d\/init.d\/cassandra)
\nActive: active (exited) since Thu 2016-09-15 04:36:47 UTC; 14s ago
\nDocs: man:systemd-sysv-generator(8)
\nProcess: 9413 ExecStart=\/etc\/rc.d\/init.d\/cassandra start (code=exited, status=0\/SUCCESS)<\/p>\n
Let\u2019s ensure that Cassandra is running using this command.<\/p>\n
[root@cassandra ~] cqlsh<\/p>\n
Connected to Test Cluster at localhost:9160.
\n[cqlsh 4.1.1 | Cassandra 2.0.17 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
\nUse HELP for help.
\ncqlsh><\/p>\n
assandra ships with a powerful command line utility, cqlsh. Launch it to perform various vital tasks with your database.<\/p>\n
[root@rmohan.com ~] nodetool status<\/p>\n
Datacenter: rmohan
\n=======================
\nStatus=Up\/Down
\n|\/ State=Normal\/Leaving\/Joining\/Moving
\n— Address Load Tokens Owns (effective) Host ID Rack
\nUN 127.0.0.1 46.21 KB 256 100.0% 7dd2b7d9-404e-4a77-a36d-cc8f55168c0d rack1
\n[root@rmohan.com ~]#<\/p>\n
Restart Cassandra<\/p>\n
systemctl restart cassandra<\/p>\n","protected":false},"excerpt":{"rendered":"
Apache Cassandra is a NoSQL database intended for storing large amounts of data in a decentralized, highly available cluster. Cassandra or Apache Cassandra is a distributed database system which manages large amounts of structured data across different commodity servers by providing highly available service with no point of failure. NoSQL refers to a database with […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[83],"tags":[84],"_links":{"self":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6589"}],"collection":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6589"}],"version-history":[{"count":2,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6589\/revisions"}],"predecessor-version":[{"id":6591,"href":"https:\/\/mohan.sg\/index.php?rest_route=\/wp\/v2\/posts\/6589\/revisions\/6591"}],"wp:attachment":[{"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mohan.sg\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}